1. Field
The present disclosure relates generally to inspection systems, and in particular, to backscatter inspection systems. Still more particularly, the present disclosure relates to a method and apparatus for detecting backscatter off of an object using a detector having a shape capable of substantially conforming to a shape of the object.
2. Background
A backscatter x-ray system is an example of a nondestructive inspection system (NDI) that uses x-rays to inspect an object. Some currently available backscatter x-ray systems include an x-ray tube, a collimator, and a detector. The x-ray tube generates and emits x-rays. The collimator filters these x-rays to form an x-ray beam using a portion of the x-rays that travel substantially parallel to a specified direction.
When the x-ray beam encounters the object, some or all of the x-rays in the x-ray beam are scattered by the object. In particular, the x-rays may be scattered off of the surface of the object and/or the subsurface of the object. The scattered x-rays are referred to as backscatter. The detector detects some or all of this backscatter. The detected backscatter may be used to generate image data for the object that can be used to form one or more images of the object. For example, the backscatter detected when the x-ray beam is directed at a particular location on the object may be used to generate an intensity value for a pixel in an image that corresponds to that particular location on the object.
The x-ray beam may be moved along the object in a selected pattern such as, for example, a raster pattern, such that image data may be generated for different locations on the object. In one illustrative example, the direction in which the x-ray beam is pointed may be changed such that the angle of incidence of the x-ray beam, with respect to the object, changes. This image data is used to form one or more images of the object that may be used to determine whether any inconsistencies are present in the object.
The detectors used in some currently available backscatter x-ray systems have a substantially planar shape. In other words, these detectors have a flat shape. The number of locations in which a backscatter x-ray system can be used may be limited when the detector in the backscatter x-ray system has a flat shape. For example, positioning a backscatter x-ray system with a detector having a flat shape relative to an object having a curved shape may be more difficult than desired.
Further, with a detector having a flat shape, the amount of backscatter detected by the detector may be less than desired for different angles of incidence of the x-ray beam with respect to the object when the object has a curved shape. In other words, the amount of backscatter detected by the detector may be less than desired for different angles of incidence of the x-ray beam when the object has a curved shape.
Consequently, images formed using the image data generated by a detector having a flat shape may not have a desired level of quality when used to detect backscatter off of a curved object. Therefore, it would be desirable to have a method and apparatus that takes into account at least some of the issues discussed above, as well as other possible issues.